Build the Editor with Which This Book Was Written

This book was originally written in XML. Before marking up a document with XML, you must decide on a DTD. A DTD (document type definition) determines which tags may be used in the markup. A common DTD for technical documents is DocBook. This book was originally a DocBook document.

Before writing this book, I needed an editor. The exercise for this section is to write a simplified version of the DocBook editor with which this book was written (Figure 26.1).